WIDEGAP A-SI-H FILMS PREPARED AT LOW SUBSTRATE-TEMPERATURE

Wide bandgap hydrogenated amorphous silicon (a-Si:H) films have been p repared by the PECVD method at a low substrate temperature (80 degrees C), controlling the incorporation of hydrogen (bonded with silicon) i nto the film. Optimizing the deposition parameters viz. hydrogen dilut ion, rf power, a-Si:H film with E(g) similar to 1.90 eV and sigma(ph) greater than or equal to 10(-4) Scm(-1) has been developed. This film exhibited better optoelectronic properties compared to a-SiC:H of simi lar optical gap. The quantum efficiency measurement on the Schottky ba rrier solar cell structure showed a definite enhancement of blue respo nse. Surface reaction as well as structural relaxation under suitable deposition condition have been claimed to be responsible for the devel opment of such material.